Constipation is a common complaint among the elderly patients with psychiatric disorders because of age.related physiologic and anatomical changes, lifestyle factors, comorbid physical and surgical disorders, medications, including psychotropics, and polypharmacy. Lack of timely reporting by patients as well as inadequate expertise of physician may contribute to significant delay in treatment and poor quality of life. Primary constipation is amenable to lifestyle modification. (dietary changes, exercise, and physical activity), fiber intake, and laxatives when necessary. Secondary constipation should be treated with managing underlying pathology or predisposing factors, including effective treatment of psychiatric disorders and rationalizing psychotropic prescription. This review article focuses on the definition, etiology, assessment, treatment, and prevention of constipation in elderly population with mental illness.

The prevalence of constipation in general population is ranging from 2% to 27%, depending on its criteria and study population.[1],[2] Constipation is a common complaint in elderly population, more commonly diagnosed in female patients (male/female ratio: 1:2–3), as reported prevalence is 26% for women and 16% for men in individuals 65 years of age or older in the community [3] and 34% for women and 26% for men in those 84 years of age and older. While in long-term care setting, constipation is reported by around 80% inhabitants.[4] In a recent study, elderly patients (older than 60 years) with psychiatric disorders were significantly associated with constipation (odds ratios 3.38–6.52), in comparison to the patients aged between 18 and 60 years (odds ratios 1.00–2.03).[5]

Aging-related factors such as decreased mobility, improper diet with low fiber and fluid intake, lack of exercise and physical activity, poor toilet habits, decreased awareness and blunted urge to defecate also predispose the risk of constipation in elderly.[6] Brain and bowel functions are interrelated as nervous tension particularly affects the bowel muscles [7] and on other side loaded bowel can cause distress, psychological problems, and impairs quality of life.[8],[9] Psychotropic medications and other drugs, sedentary lifestyles, unhealthy nutritional habits, relative pain insensitivity as a result of psychiatric disorders, medical and surgical comorbidities also contribute to constipation.

In view of potentially serious consequences of chronic constipation in elderly patients, its prevention, comprehensive assessment, and treatment are important. Although there are several studies on constipation per se and constipation in elderly population, but literature is scarce on “constipation in the elderly patients with psychiatric disorders.” Hence by synthesizing information available from articles on “constipation” in “elderly” with “psychiatric disorders” published in PubMed and Google Scholar, we aimed to provide an overview of definition, etiology, assessment, treatment, and prevention of constipation in elderly population with mental illness.

Definition of Constipation

Constipation is simply defined as the passage of small hard stool infrequently and with difficulty. Most physicians usually diagnose constipation objectively by measuring the stool frequency. Paradoxically, most of the patients report constipation with subjective measures with predominant focus on their symptoms such as hard stools, infrequent stools, the need for excessive straining, a sense of incomplete evacuation, excessive amount of time spent on the toilet, rather than the stool frequency. Therefore, it is recommended to use the Rome III criteria for defining constipation.[10]

Rome III criteria (2006) diagnose constipation in the presence of at least 2 of the following criterion in at least 25% time during defecation: Straining; lumpy or hard stools; sensation of incomplete evacuation; sensation of anorectal obstruction/blockage; need for manual maneuvers to facilitate defecation; and fewer than 3 defecations per week.[11],[12] Constipation is considered chronic if such symptoms persist for 6 months or more.[13],[14] In the absence of medical or surgical cause, constipation is considered idiopathic or simple.

Pathophysiology

Normal defecation requires several gastrointestinal actions in following sequence: Relaxation of the puborectalis muscles, descent of the pelvic floor with straightening of the anorectal angle, inhibition of segmental colonic peristalsis, contraction of the abdominal wall muscles, and subsequently, relaxation of the external anal sphincter with expulsion of feces.

Following anatomical and physiological changes may produce constipation in elderly.[15]

These can be broadly classified into two categories - pelvic floor dysfunction and slow colon transit time.

Pelvic floor dysfunction involves laxity of the pelvic floor muscles with impaired rectal sensation and decreased luminal pressure in the anal canal, which leads to chronic constipation, more commonly in elderly women.[16],[17],[18]

Slow colon transit time is presentence with reduced high-amplitude propagated contractions in the colon, which further leads to slow transit of feces, abdominal discomfort, bloating, and renders the feces hard and fails to produce adequate rectal pressure for defecation reflex.

Normal transit constipation is a functional gastrointestinal disorder, with normal colon transit time and stool frequency. Such patients perceive constipation due to difficulty in defecation with the presence of hard stools. This presentation is similar to irritable bowel syndrome (IBS) with constipation, except the presence of abdominal pain or discomfort in patients with IBS.[19]

Medication-induced gastrointestinal hypomotility is primarily mediated through antagonism of muscarinic anticholinergic activity.[21],[22] Besides this, many patients with schizophrenia also receive anticholinergic medications for the treatment of extrapyramidal side effects [23] and sedation due to histamine H1 receptor antagonism also results in inactivity, and further leads to constipation.[24]

High-potency typical antipsychotic agents and clozapine have greater risk for constipation due to high anticholinergic activity while aripiprazole and ziprasidone have lower risk for constipation. Both anticholinergic drugs and antipsychotics with anticholinergic properties are significantly associated with risk of ileus.[32] Despite the widespread use of atypical antipsychotics, anticholinergic co-prescription is still in vogue, which needs serious relook in prescribing practice.[32]

Opioids cause constipation by binding to specific receptors in the gastrointestinal tract and central nervous system, resulting in reduced bowel motility through direct action and indirectly with anticholinergic mechanisms. The delayed colonic transit time causes excessive water and electrolyte reabsorption from feces, which further dehydrates stool and increases constipation.[33],[34]

Elderly patients with chronic pain are less active and often treated with opioid analgesics, or on other side, elderly may be already dependent on opium or other opioid preparations or receiving opioid substitution therapy (like methadone). Majority of such patients report constipation.[35],[36] Therefore, they should be routinely advised for drinking adequate amounts of fluids, eating fiber-rich foods, increasing physical activity, and exercising regularly, etc.

Therapist may consider a combined stimulant laxative with a stool softener when initiating opioids. In general, bulking agents are not recommended for patients with opioid-induced constipation, especially if the patient has poor fluid intake or immobility, as they increase the risk of bowel obstruction. Oral naloxone (an opioid antagonist) alleviates opioid-induced constipation without loss of analgesic effects.[37] PAMORA (subcutaneous or oral) and an oral chloride channel activator have received Food and Drug Administration approval for opioid-induced constipation. Lubiprostone is a promising and well-tolerated agent for this indication.[38]

Nicotine

Nicotine increases intestinal peristalsis by acting on the parasympathomimetic system, therefore, constipation is reported as a possible tobacco withdrawal symptom, usually presents within the first few days, and relieves in 2–3 weeks.[39] It can also present as side effect of medications used (bupropion and varenicline) for quitting tobacco.

To manage tobacco-related constipation, lifestyle modification and magnesium salts are advised. If constipation persists then, neostigmine is prescribed, which has parasympathomimetic activity.[40]

The clinical presentation of elderly patient suffering from constipation is heterogeneous and different from adult populations.[44],[45] Straining and hard stools are the predominant complaints nearly half of the elderly population in community.[3],[46]

Many elderly patients experience fecal seepage and usually misdiagnosed with fecal incontinence.[47] Severe constipation may alter gastric motility and result in delayed gastric emptying, concomitant dyspepsia, abdominal cramping, bloating, flatulence, heartburn, nausea, and vomiting.[48],[49],[50] Sometimes, elderly patients with impaired cognitive abilities may also present with nonspecific symptoms such as agitation, anorexia, or decline in overall functioning.[51]

Diagnostic assessment is to be done as per an evidence-based approach given by American College of Gastroenterology Chronic Constipation Task Force.[53]

Obtain detailed history to determine whether symptoms are secondary to any diseases or medications. Medical history should include the use of medications, including psychotropic medication, anticholinergic drugs, opioid analgesics, substance abuse including opium and tobacco, coexisting medical and surgical disorders, dietary habits, physical activities, and general psychosocial situation

Proper management of constipation should be aimed to relieve associated symptoms, along with restoring normal bowel habit (i.e., passage of a soft, formed stool at least three times a week, without straining), and quality of life.[54] Treatment algorithm is similar for elderly and adult population.

Following stepwise approach is recommended for managing constipation in elderly population [55]

Step 1: Establish the diagnosis of constipation

Define constipation as per Rome III criteria and enumerate the presenting symptoms.

To reduce or resolve constipation, reversible causes should be treated first.

Step 4: Medication history

As mentioned earlier, numerous drugs may cause or contribute to constipation, therefore detailed medication history is very important. If feasible, therapist should decrease the dose, discontinue the medication, or switch to another drug with a lesser propensity of constipation.

Step 5: Lifestyle modification

A regular toilet routine with toileting in the morning, even without urge, is recommended for elderly. Adequate hydration is recommended for patients with low intake or who are taking bulk-forming agents, and who are not advised fluid restrictions (e.g., heart or kidney failure). Soluble fibers (e.g., psyllium) are preferred and have better evidence than insoluble fibers (e.g., bran).[56] To minimize gastrointestinal side effects (e.g. flatulence, bloating), fiber should be titrated gradually (e.g., increased by 5 g/week) up to the dose of 20–30 g/day. Patients with slow-transit constipation or pelvic floor dyssynergia poorly respond to fiber supplementation.[3]

Recommended therapy begins with a bulk-forming agent, then an osmotic laxative followed by a stimulant laxative, if need arises.[56],[57] Fecal impaction is treated with manual disimpaction, lubrication of rectum and anus, and enema.

Biofeedback therapy is indicated for pelvic floor dysfunction or dyssynergic defecation type of chronic constipation. It enables the patient to relax the pelvic floor muscles by retraining of the sensation and control of the anorectum and pelvic floor and eliminates paradoxical contractions during the process of defecation. It has been found efficacious in several controlled trials [58],[59] and recommended for adults and elderly patients.

Bacteriotherapy (probiotics)

Lactobacillus and Bifidobacterium are symbiotic floras in the large intestine that protect from the harmful pathogens and maintain mucosal health. Both floras are reportedly low in patients with chronic constipation.[60] Prospective trials have shown improvement in constipation with Lactobacillus[61] and Bifidobacterium supplementation.[62] However, it is not recommended in routine practice due to lack of high-quality evidence [Table 4] and [Table 5].[10],[63]

Table 4: How to manage constipation related to psychiatric disorder or psychotropics

Preventive strategies such as high fiber diet, adequate hydration, regular exercise, and physical activity should be promoted. Psychotropic drugs should be appropriately selected and started with low dose and slowly titrated in elderly patients and polypharmacy should be avoided.[66] To obviate severe consequences of constipation early detection, monitoring over the course of treatment, routine prophylaxis, and early treatment are important.

Conclusion

Elderly patients with psychiatric disorders often have low health expectations and are less likely to complain for constipation. Sometimes, they have problem in communication due to cognitive impairment while other side, this all is considered part and parcel of aging by health professionals. Therefore, assessment of constipation in patients with severe mental illness must be included in the comprehensive management by mental health professionals.[67] In view of multiple risk factors, physical comorbidities, and medication, stepwise approach is advised for treating constipation [Figure 1].

Figure 1: Algorithm for management of constipation in elderly patients with psychiatric disorders

At the first step of management, therapist should look and correct the underlying causes of constipation.[68] Instead of starting further treatment for constipation in the first instance, dose adjustment of concomitant psychotropics and treatment rationalization should be considered. Treatment should be started with nonpharmacological approaches, including patient and caregiver education, toileting habits, abdominal massage, high-fiber diet, regular physical activity, and exercise (e.g., prompting to walk to the toilet, exercise for chair-bound patients). In pharmacological approaches, fiber supplements, stool softeners, osmotic, and stimulant laxatives, and the secretagogues are available. However, fiber and laxatives are commonly advised as initial treatment in constipation. Biofeedback should be considered for the patients with pelvic dyssynergia or pelvic floor dysfunction. This review highlights the vital need for better knowledge base, assessment, management, and prevention of constipation in elder patients with psychiatric disorders.